Tubular organs in the body may have a convoluted cavity configuration. The gastrointestinal tract, for example, starts from the oral cavity and proceeds through the esophagus, stomach, duodenum and small intestine, which may be a long tube that may fold many times to fit inside the abdomen. The small intestine is connected to the large intestine, which begins with the cecum, a small saclike evagination, then continues with the ascending colon, transverse colon, descending colon and the sigmoid (S-shaped) colon to the rectum. These body lumens may suffer from pathologies, which may affect the anatomy or configuration of the lumen. For example, strictures, narrowing or closure of a normally configured lumen may be caused by calcification or by the presence of scar tissue or a tumor. Strictures of the esophagus may be a common complication of chronic gastroeosophagaeal reflux disease (GERD). Acute, complete obstruction of the esophagus may occur when food may be lodged in the esophageal stricture. Endoscopy may usually be employed to retrieve the food and relieve the obstruction.
Methods for diagnosis of body lumens may usually be symptom related or invasive. Non-invasive techniques of diagnosing the gastrointestinal (GI) tract may include utilizing solid non-degradable ingestible autonomous electronic or magnetically marked capsules. These autonomous capsules may include capsules for measuring motility in the GI tract, gastric pH (such as the Heidelberg capsule) and in-vivo temperature (such as the CoreTemp™ capsule). Also, gastric transit may be measured by using biomagnetic measuring equipment such as a magnetically marked capsule, which is a solid non-degradable oral dosage form containing powdered magnetite encapsulated in silicone rubber (W. Weitschies, R. Kotitz, D. Cordin, L. Trahms, (1997), J Pharm Sci, 86:1218-1222). Such capsules may typically be propelled through the GI system by peristalsis. These non-invasive methods may enable reaching parts of the intestine, for example, distal parts of the small intestine aejunum and ileum) that may not be reachable by other methods. However, in rare cases of severe strictures in the GI tract, swallowing of a solid bolus (such as an electronic or magnetically marked capsule) may cause obstruction of the GI tract.
Non-invasive methods for detection of strictures, specifically in the GI tract, usually include x-ray series that may be based on intake of x-ray opaque (radio-opaque) material (barium sulphate, gastrographine, or others), for example a barium pill (solid bolus) that dissolves rapidly for testing strictures in the esophagus. The material may reside for some time on the walls of the GI tract, enabling examination of the x-ray images of the GI tract. This technique may have several drawbacks, namely, low detection rate and exposure to x-ray radiation.
In-vivo devices, pills, or other medical systems may need to pass through the GI tract. However, it may be difficult to predict if such devices, pills, or systems may achieve safe passage through the GI tract, short of actually attempting to pass the objects through the tract.